"you can use my stuff, as long as you give back what you make from it"

I've read the GPL, and I feel that this is by far the most beautifully to-the-point and most honest real-world representation about the requirements of the GPL that was ever put down in a single, brief sentence.

Some people might disagree with this, and I'm sure those people who do would also argue that the act of jumping of a 1000ft cliff without a parachute being fatal is a bald-faced lie (because technically, it's the a priori sudden stop that kills you; so you're really just spreading FUD about jumping from great heights, as jumping itself has no immediate requirement of death).